1. Field of the Invention
This invention pertains generally to agricultural planting equipment.
2. Description of the Prior Art
The efficient production of crops requires that planters meet certain primary design objectives which are: accurate planting depth, seed and soil contact, and accurate seed spacing. If the seed is planted too deep, the plant may not emerge. If planted too shallow, there may not be enough moisture for germination. Good seed and soil contact is needed for germination but same must be provided without undue soil crusting to inhibit plant emergence. Accurate spacing of seed is necessary to provide equal access to sun, water and nutrients and for uniform stands.
Most planters attempt to meet the noted objectives but with varying success. For example, a conventional and fairly popular planter which is connected to a tool bar by upper and lower parallel links for vertical parallel movement as the planter follows the ground surface, places the adjustable (pivotally mounted) gauge wheels, which also support the planter, close to the disks ostensibly for accurate furrow depth control. Yet rearwardly (pivotally) mounted spring loaded (adjustable) furrow closing wheels are also utilized. Inasmuch as the planter is also supported thereon, gauging is really done at both locations, so accurate furrow depth is not achieved. In addition, the disk openers do not carve out perfect V-shaped trenches or furrows, but instead leave some soil therein. The seed placed in the furrow therefore is not necessarily at the maximum depth of the trench but may be on the soil therein and thus is not located at a desired depth. Also seed bounce in the furrow is common with today's planting speeds even with conventional plate type (gravity drop) dispensers. This affects seed spacing and depth as the seed may be covered by the soil before it comes to rest. Inasmuch as the seed depth varies, the furrow closing (or pinch) wheels may also not provide the soil contact desired therewith when the seed is not at the desired depth. Also the undesirable soil compacted by the gauge wheels is utilized to fill the furrow. Thus the noted planter objectives are not successfully met.